In new guidelines published today, the World Health Organization recommended that everyone diagnosed with HIV immediately receive antiretroviral therapy, and recommended preventative antiretroviral treatment options for those at "substantial risk" of infection. The new guidelines mean nine million more people living with HIV should be treated, and recommends protective treatment for millions more.

"The expanded use of antiretroviral treatment is supported by recent findings from clinical trials confirming that early use of ART keeps people living with HIV alive, healthier and reduces the risk of transmitting the virus to partners," WHO said in a statement. As part of the guidelines, WHO said it was also broadening its recommendations for who should have pre-exposure antiretroviral treatment available. Previously, WHO had recommended the treatment for populations at high risk, including men who have sex with men and people who inject drugs. The new guidelines widen that to anyone meeting the criteria for "substantial risk."

In total, under the new guidelines, treatment is recommended for all of the approximately 37 million people infected with HIV worldwide. Previous guidelines had recommended it for about 28 million.